The Hulk's trademark shambling jumps weren't just motion-captured on the fly — every lurch was planned out carefully in advance, judging from this newly released behind-the-scenes video from the DVD, which comes out Oct. 21. The movie's VFX masters taped Edward Norton rolling about on the floor of an office to figure out the Hulk's awesome gait. It's quite funny, and a bit of a lightsaber-fight-in-the-garage moment, but that's dedication. Other DVD goodies, out now, include a feature on casting Norton in Hulk, plus one deleted scene and some footage of Tim Roth on the run.Casting the Hulk: More Therapy For Bruce: Tim Roth In Action: